The clock rate and processing speed of microprocessor cores, such as are used in a computer central processing unit (CPU), typically increase with the introduction of new core types and families. The clock rate is the frequency, measured in cycles per second (Hertz), at which a computer performs operations such as adding two numbers or transferring a value from one component to another. The data on which the microprocessor operates are delivered to it from other devices and components, each connected directly or indirectly to the microprocessor via sets of wires called data busses connected to ports on the microprocessor.
As the speed of a microprocessor core increases, the speed with which the core is able to process data also increases. However, the speed of the computer components other than the core, such as memory delivering data to the core, may not increase, or may not increase as quickly as the speed of the core. In addition, there are typically many different devices and components to and from which the core communicates data, and many different external links to the core through which the data are communicated. Such a collection of data links is referred to as a link fabric. Typically data from different sources are delivered to the processor through the link fabric at different speeds and at different clock frequencies. One problem that arises as microprocessor core speed increases and exceeds the bandwidth of the data from the devices connected to it is how to interface multiple agents on a link fabric to a fast core so that the core's processing capability is efficiently utilized.
Current solutions for increasing bandwidth to a core include increasing the number of interlinks and/or the speed of the interlinks, such as by increasing link interconnect clock speeds. Also, wider datapaths capable of delivering more data per cycle to the core have been implemented. These solutions typically require major computer manufacturer, chipset, and link specification work to align on a new baseline infrastructure.